Automatic pressure-operated switch



W. L. HAMILTON.

AUTOMATIC PRESSURE OPERATED SWITCH. APPLlVcAnoN man SEPT. lo, 191B.

13121340, y Patented July 4, 1922.

v SHEETSAHEET 1.

A TTRNEYS W. L. HAMILTON.

AUTOMATIC PRESSURE OPERATED SWITCH.

APPLICATION HLED SEPT. 1o. 1918.

1,421,940. f Patent-ed July 4, 1922.

2 SHEETS-SHEETfZ.

I muy|||||m|||||||||||||||||||||||||||||||||u| WITNESSES IN VEN TORUNITED STATESA PATENT oFElcE.

l WILLIAM L. HAMILTON, OF BANGOR, MICHIGAN. i

AUTOMATIC PRESSURE-OPERATD SWITCH.

T o all ulw'm. it may concern:

` Be it known that I` 'WILLIAM L. 'HAMIL- ToN, a citizen of the UnitedStates, and a residentof Bangor, in the county of Van Buren and State ofMichigan, have invented a new and Improved Automatic Pressure- OperatedSwitch. of which the following is a full. clear, and exact description.

The invention relates to electric motors used for operating pumps` andits object is to provide a new and improved automatic pressure operatedswitch arranged to automatically stop the electric motoras soon as thedesired pressure is reached and to restart the lnotor immediately7 afterthe pressure decreases below thepredetermined pressure to bemaintainedby the switch. Another object is to provide-a pressureoperated switch which is very simple.' durable vin construction andexceedingly quick in stopping the motor whenever the desired pressure isreached.

A practical embodiment of the invention is represented in thewaccompanying drawings forming a part of this specification. in which--similar characters of reference indicate corresponding parts in allthe views.

Figure 1 is a sectional side elevation of the automatic preure operatedswitch with the parts in normal position;

Figure 2 is a similar view ofthe same with the electric switch in openposition;

Figure 3 is a sectional plan -view of the automatic pressure operatedswitch on the line 3-3 of Figure 1; `and Figure 4 is a perspectiveviewof the controlling lever. The support l0 of the automatic pressureoperated switch is provided with a chamber l1 closed on top by adiaphragm 12 and provided at one side with an inlet 13 connected with `areservoir 'containing compressed air or other fluid under pressurepumped into the reservoir by a pump actuated by an electric motor.

On the top of the diaphragm 12 rests loosely a plate 15 engaged b v lugs16 depending from the fork members 17' of a lever 18 fulcrumed at 19 onthe top of a ring 20 rest-ing on the top margin of the diaphragm 12 andsecured to the support 10 by screws 21. the lever 18 are provide-d ontop with a seat 25 in which is seated a pressure plate 26 engaged by thelower end of a spring 27 supported at the top by a plateA 28 en-Specification of Letters Patent.

The fork members 17 o'f lPatented Julyr 4, 1922.

Application led September 10, 1918. Serial No. 253,489.

gaged by an adjusting screw 29 screwing in a bracket 30 forming part oflthe ring 20. By adjusting the screw 29 the tension of the spring 27 canbe regulated laccording to the pressure to be maintained in thereservoir. The top of the plate 15 is provided with a boss 35 projectinginto the lower end of a light spring 36 interposed between the plates 15and 26. The spring 36 holds t-he plate l'centrally in position on thetop of the diaphragm 12, it being understood that the upper portion ofthe spring 36 extends -between the fork members 17 of the lever 18. Thefree end of the lever 18 is preferably provided with a fork 40'carryinga transverse pin 41 connected with one end of a tension spring 42 andattached at its other end to a rod l' n53 connected with the electricVmotor so that when the switch 45 is in closed positionthe motor is"running and when the switch is opened ythe motor is stopped. Then theswitch is in closed position the centers of the pins 41 and 43 are belowthe center of the fulcrum 50 and the tension spring 42 now securelyholds the movable member 44vof the switch 45 in closed position, thatis. in engagement with the fixed contacts 55. When the pressure in thereservoir and consequently in the chamber 11 exceeds a normalpredetermined pressure then the diaphragm 12 is moved upward a suicientdistance to cause the lever 18 l to swing upward by the action of theplate `15 and lugs' 16. When the lever has swung upward a distance tolothe center of the pin 41 passes below the center of the fulcrum thenthe switch member 44 is quickly swung downward into engagement with thecontacts to close the switch and to re-start the motor.

In practice, the movable switch member 4I is made of two side piecesconnected with each other by a crossbar or' hard rubber or otherinsulating material and adapted to rest on an adjustable stop screw 61attached to the support l0. The upward movement of the switch member Mis limited by the crossbar 60 abutting against the under side of thelever 18, as plainly shown in Figure 2. The pin 43 is connected with theside pieces of the movable member l0 by insulating blocks 65, as plainlyindicated in Figure 3.

The automatic pressure controller shown and described is very simple anddurable in construction and not liable to get easily out of order. Itwill also be noticed that the spring 2T of the pressure controller canbe readily adjusted to the pressure to be maintained in the reservoirand the switch is eX- c-eedingly quick in action both in openingr andclosing.

-Having thus described my invention, I claim as new and desire to secureby Letters Patent l. In a pressure regulator, a diaphragm exposed topump pressure,a. leverhaving depending lugs, a spring supporting plateheld on the lever, a spring bearing on the said supporting plate, apressure plate on the said diaphragm and engaged by the said lugs. thesaid pressure plate having a rising boss, a light spring interposedbetween the said pressure plate and the under side of the saidsupporting plate, the light spring engaging the said boss, a switchhaving a pivoted member, and a tension spring connect- 'ing the free endof the said lever with the said pivoted switch member.

2. In a pressure regulator. a support. a diaphragm exposed to pressure,a pivoted and spring pressed lever actuated b v the diaphragm. saidlever being provided with an opening. a base carried b v the support. aswitch mounted on the base. and having a pivoted member. a casing`mounted on the base and into which the lever extends. a rod securing thecasing base and support -together. said rod passing through the apertureof the lever. and a tension spring c'onnecting the lever with themovable member of the switch.

3. In an automatic pressure actuated switch. a diaphragm exposed to pumppressure. a lever having depending lugs, a spring bearing on the lever,a pressure plate on said diaphragm and engaged b v said lugs. a lightspring interposed between said pressure plate and the lever. a switchhaving a pivoted member, and a tension spring connect'- ing the free endof said lever with said pivoted switch member.

YILLIAM L. HAMILTON.

